SARA voting: easier-to-describe MAS

[Jameson Quinn]

Support Accept Reject Abstain voting works as follows:

• Voters can support, accept, reject, or abstain on each candidate. Default is abstain.
  
• Call a candidate "acceptable" if they are rejected by 50% or less and supported or accepted by over 25%. If any candidates are acceptable, eliminate all who aren't.
  
• Give remaining candidates 2 points for each "support", 1 point for each "accept", and half a point for each "abstain". Highest points wins.
  

This moves a bit away from the Bucklin roots of MAS, but it further reduces the instability of cooperation in a CD scenario.

[Jameson Quinn]

Here's a new definition of SARA:

Support Accept Reject Abstain (SARA) voting is very similar to Majority Acceptable Score voting, which is the graded Bucklin method which uses 3 grade levelsand breaks median ties using Score voting. SARA works as follows:

1. Voters can support, accept, reject, or abstain on each candidate. Default is abstain. Candidates get 2 points for each percent of "support" and 1 point for each percent of "accept", for a total of 0-200 points.
   • "Support" helps a candidate the most, "reject" hurts the most. "Accept" helps less than support, and is good for helping a second-rate candidate beat a third-rate one. "Abstain" helps a candidate avoid elimination in step 3 but hurts them in steps 2 and 4; it's good for a second-rate candidate when there's a first-rate one who can beat them, or for a candidate you're not sure about.
2. Eliminate any candidates with under 50 points.
   • 50 points would be the score of a candidate supported by 1/4 or accepted by 1/2. Anything less than that probably indicates a lesser-known candidate who got a lot of 'abstains'; eliminating them here ensures they won't be the only candidate remaining after step 3.
3. Eliminate any candidates rejected by over 50%, unless that leaves nobody.
   • If possible, the winner shouldn't be somebody opposed by a majority.
4. Highest points wins. In case of a tie, fewest rejections wins.
• This finds the candidate with the widest and deepest support.

...

This does not pass the CD criterion; in the scenario (expressed as Support>Accept>Abstain>Reject)

28: A>>B>C
27: B>>>AC (honest is B>>A>C)
45: C>>>AB

... the truncation by the B voters successfully elects B.

However, it does avoid a slippery slope. That is to say, in the above scenario, even though A leads B by just one vote, a mere two strategic B voters cannot elect B by truncating:

28: A>>B>C
2: B>>>AC
25: B>>A>C
45: C>>>AB

A wins, even though B would win with the analogous truncation in score or Approval.

I think that this "no slippery slope" property is sufficient to give good CD performance in the real world. If you assume that most other voters in your faction will not be trying CD strategy, there is no incentive to try it yourself, so the ball never gets rolling.

On the other hand, it can avoid center squeeze:

28: A>>B>C
27: B>>A>C
3: C>B>>A

42: C>>>AB

B, the CW, correctly wins.

If I'm right that this kind of system avoids CD strategy, the only effective cognitive burden of this method is the decision between "accept" and "abstain". You should "accept" a lesser evil against a greater evil; you should "abstain" if you think that your favorite can win. This is, I think, the minimum possible cognitive burden for a method that does well on both CD and center squeeze; and it's distilled to its purest form.

[Jameson Quinn]

I've tweaked the wording for SARA again. The only substantive changes in outcome from this new wording is the change from "50 points or more" to "more than 50 points".

Here's the latest wording, in 3 steps:

Support Accept Reject Abstain (SARA) works as follows:

1. Voters can support, accept, reject, or abstain on each candidate. Default is abstain. Candidates get 2 points for each percent of "support" and 1 point for each percent of "accept", for a total of 0-200 points.

1. • "Support" the best candidates (perhaps a quarter of them), "reject" the worst (perhaps half of them). "Accept" and "abstain" are for the ones in the high middle range. For those, "accept" if you want to help them beat somebody worse, and "abstain" if you could live with them but are hoping for somebody better.
2. Eliminate any candidates rejected by over 50%, unless that leaves no candidates with over 50 points.
   • If possible, the winner shouldn't be somebody opposed by a majority. But this shouldn't end up defaulting to a candidate who couldn't at least get accepted by over 1/2 or supported by over 1/4 (as in, a majority subfaction of a divided majority, such as Nashville voters in the example below).

1. Highest points wins. In case of a tie, fewest rejections wins.
   • This finds the candidate with the widest and deepest support.

2016-10-22 18:24 GMT-04:00 Jameson Quinn <jameso...@gmail.com>: